1. Field of the Invention
This invention relates to product filling machinery and particularly to machines and methods for filling an intermediate receptacle with a predetermined amount of product for transfer to an ultimate container.
2. Description of the Prior Art
My U.S. Pat. Nos. 3,517,708, issued June 30, 1970; No. 3,621,891, issued Nov. 23, 1971; and No. 3,696,581, issued Oct. 10, 1972 describe rotary-drum machines for filling intermediate receptacles with predetermined amounts of materials for transfer to ultimate containers, and their disclosures are incorporated herein by reference.
In these prior machines, elongated rake members spaced circumferentially around a horizontal or inclined drum mounted for rotation about its axis each have a plurality of inward-projecting tines for picking up portions of materials such as food products in the bottom of the drum as the drum rotates and for carrying the portions to a predetermined release point near the top of the drum for discharge onto a chute or shaker tray for delivery into a line of intermediate receptacles extending through the drum. The receptacles are fastened to an endless conveyor that includes means for shaking the receptacles as they are filled to eliminate voids and to obtain a uniform packing density in each receptacle corresponding to a predetermined package amount. After being filled, the intermediate receptacles are transported by the conveyor to a separate station outside the drum where their contents are transferred to a line of ultimate containers on a second conveyor that is synchronized with the movement of the receptacle conveyor.
One method shown in these prior patents (U.S. Pat. No. 3,517,708) for transferring products from the intermediate receptacles to the ultimate containers includes pivoting each receptacle on an arm for 180.degree. rotation outward around the line of the conveyor to an upended position over the container to which the product is to be transferred. A close-fitting cylindrical shell located on the arc of receptacle rotation prevents the loss of any material until each receptacle is fully upended and has advanced to a position directly over the corresponding container.
An alternate method shown in U.S. Pat. No. 3,621,891 and 3,696,581 for transferring products involves the use of automatically controlled doors mounted directly under an open-bottom receptacle, the doors being rotatable in synchronism from a horizontal position where they close the bottom of the receptacle to a vertical position over the container line where they funnel the product into the underlying container.
The above-described product transfer methods of my prior inventions require relatively complex mechanical arrangements for synchronizing the receptacle rotating or door opening mechanisms, as well as a large number of parts that add to the cost and difficulty of cleaning these prior machines. In addition, the intermediate receptacles used in these machines comprise a single open volume, exactly sized to accommodate a predetermined weight of uniformly packed products. For packing stringy or tangly products, they may include various cutters and soft rollers for trimming excess materials hanging over the edges of the containers and for compressing materials to a uniform packing density at a height even with the top edges of the receptacles.
In many filling applications, instead of filling to a predetermined weight or packed volume of materials it is desired to fill a predetermined number of items into a container, the items having a relatively uniform size. Examples in the packaging of food include such items as meatballs, crab cakes, croquettes, egg rolls, doughnuts, graded size fruits, and the like. In such applications it is quite difficult to fill accurately and repeatably a single open receptacle with the exact number of items desired in each ultimate container because an individual item may take only a small percentage of the total receptacle volume and the shape of the receptacle volume does not conform to the shape of the items so that extra items may squeeze into corners of the receptacle. Also, in many packaging applications it is desirable to place items in desired relative positions in a container as, for example, apples, peaches or oranges in columns and rows on a flat tray or in a partitioned box. Such predetermined placement cannot be obtained reliably by merely filling a single-volume transfer receptacle with the desired number of items to be packaged in each container.